Exploring E/M: Modern Physics and Its Importance

In summary, the experiment demonstrates the important concept of a v x B (vector cross product) force on a charged particle in a Helmholtz coil. The force on the electron is perpendicular to both its velocity and the magnetic field. This was very important for determining the mass of the electron and proton. But in order to get the mass, the charge had to be determined. So this is why Milliken's oil drop experiment (1913) was also so important. Knowing the electron mass from e/m and Milliken's measurement, the electron mass (actually mc2) could be used to calculate the Rydberg energy (13.6 eV) using the first quantum mechanical description (Bohr model) of
  • #1
sirous666
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What is importance of finding E/M?
I am doing a project on E/M and helmholtz coil. I heard that E/M is beginning of the Modern Physics. Can you tell me more about this experiment and why is it so important to know this ratio?
I also want to be refereed to some sources in which i can get whole a lot of information about this experiment and it's significance.
Please provide me with as much sources as you can.
 
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  • #2
By E/M do you mean electron's charge divided by the mass of the electron (usually denoted e/m)? e/m can be used to find some fundamental constants (e.g. e, or m), after some other experiments are made. e/m itself, I'm not sure has too much significance...
 
  • #3
First, the e/m experiment itself demonstrates the very important concept of a v x B (vector cross product) force on a charged particle in a Helmholtz coil. See attached thumbnail. The force on the electron is perpendicular to both its velocity and the magnetic field.

The measurement of e/m for electrons and protons was very important for determining the mass of the electron and proton (and other charged particles). But in order to get the mass, the charge had to be determined. So this is why Milliken's oil drop experiment (1913) was also so important. Knowing the electron mass from e/m and Milliken's measurement, the electron mass (actually mc2) could be used to calculate the Rydberg energy (13.6 eV) using the first quantum mechanical description (Bohr model) of the hydrogen atom. This could then be used to compare to laboratory measurements of the wavelength of observed atomic transitions (Balmer, Lyman, Paschen etc.).

Look up the url in the thumbnail for more information on the e/m experiment..

Bob S
 

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  • #4
Bob's answer is a lot better than mine...listen to him haha.
 

FAQ: Exploring E/M: Modern Physics and Its Importance

What is E/M and why is it important in modern physics?

E/M stands for electromagnetism, which is the study of the relationship between electricity and magnetism. It is important in modern physics because it is a fundamental force that governs many natural phenomena, including the behavior of atoms, light, and matter.

What are some practical applications of E/M in our daily lives?

E/M has numerous practical applications, such as in the generation and transmission of electricity, electronic devices like computers and smartphones, medical imaging technologies like MRI machines, and many more.

How does E/M relate to other branches of physics?

E/M is closely related to other branches of physics, such as mechanics, thermodynamics, and quantum mechanics. It is one of the four fundamental forces of nature, along with gravity, the strong nuclear force, and the weak nuclear force, and it plays a crucial role in understanding the behavior of matter and energy.

What are some key discoveries and theories in the study of E/M?

One of the most significant discoveries in the study of E/M is that electricity and magnetism are two different manifestations of the same fundamental force. This was first demonstrated by James Clerk Maxwell's equations, which unified the theories of electricity and magnetism. Other important theories include Coulomb's Law, Faraday's Law, and Ampere's Law.

How has our understanding of E/M evolved over time?

Our understanding of E/M has evolved significantly over time. Early civilizations were aware of electricity and magnetism, but it wasn't until the 17th and 18th centuries that scientists began to study and understand its properties. The 19th century saw major advancements in the field, including the formulation of Maxwell's equations, which led to the development of electromagnetism as a unified theory. Today, our understanding of E/M continues to evolve, with ongoing research and discoveries in areas such as quantum electrodynamics and string theory.

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